I Upgrade Alone

The "door" connecting the world to other dimensions was opened, and various monsters continued to appear. As a result, demon hunters with different abilities also appeared and were called "hunters." Su Qiuyu is an E-class hunter with the weakest strength. During a challenge mission, he encountered a terrible hidden challenge. At the moment of life and death, he actually got an upgrade system! With the use of the system, can he become the strongest hunter? The above is a serious introduction. If I am not serious, I am still thinking... This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.